Cigarette lighters



July 18, 1967 H. LOWENTHAL CIGARETTE LIGHTERS Filed Oct. 27, 1965 HANS LOWENTHAL y L1 oknlulzm, Mu-Lw-ll or r zg United States Patent 3,331,223 CIGARETTE LIGHTERS Hans Lowenthal, London, England, assignor to Colibri Lighters Limited, a British company Filed Oct. 27, 1965, Ser. No. 505,329 Claims priority, application Great Britain, Nov. 26, 1964, 48,131/ 64 11 Claims. (Cl. 677.1)

There has been proposed in co-pending U.S. application Ser. No. 457,683 filed May 21, 1965 and assigned to the same assignees as this application, a cigarette lighter having an igniting mechanism with a flint guide Which extends through or beside the usual fuel reservoir and along which a flint is urged into engagement with an abrasive element such as a flint wheel. However, instead of using the conventional helically coiled compression spring acting directly behind the flint within the guide, the lighter is arranged so that in use the pressure of a compressed gas contained in the lighter is used in urging the flint along the flint guide into engagement with the abrasive element. This has a number of advantages, for example, a longer flint can be used. There are however disadvantages particularly resulting from temperature/pressure considerations.

In accordance with the present invention, a flint guide for a cigarette lighter, the igniting mechanism of which utilizes the pressure of a compressed fluid (gas or liquid) to urge the flint into engagement with the abrasive element, is provided with a sealed enclosure that contains fluid under super atmospheric pressure and with two members which are movable in communication with the enclosure, the first of the members being urged resiliently to move in a direction to compress the fluid in the enclosure and the second member being urged to move under the pressure of the fluid in the enclosure and, when the flint guide is fitted with a flint, causing the flint to be urged out of the flint guide and, in use, against an abrasive element of the cigarette lighter, the aggregate efiective area of the first member exposed to the enclosure perpendicular to its direction of movement being greater than that of the second member.

With this arrangement, the first member always takes up an equilibrium position in which the excess pressure of the fluid balances the resilient pressure applied through the first member and a corresponding force is transmitted to the flint by means of the second member. This again enables a long flint to be used. The use of the fluid between the first and second members enables the source of resilient pressure to be positioned other than directly behind the flint in the guide and this not only provides an extremely compact arrangement but enables an even longer flint to be used. Owing to the greater effective area of the first member, there will be a mechanical advantage and velocity ratio both of less than unity between the second and first members with the natural consequence that the maximum range of movement of the first member during the consumption of a flint can be made appreciably less than the length of the flint itself. This means that the maximum fractional change in the stress of the resilient source can be made small so that the overall change in pressure produced by the resilient source during the full consumption of the flint can be made small enough to be insignificant.

The source of resilient pressure acting on the fluid in the enclosure through the first member may take a variety of forms. For example the first member itself may be the source of resilience and may be a rubber or rubber-like sack or balloon, through the neck of which is sealed one end of a tubular flint tube. The interior of the flint tube will be in communication with the interior of the sack through an opening in the wall of the tube within the sack so that the enclosure will be defined by the interior of the sack together with the interior of the flint tube behind a piston or even the flint itself which forms the second member within the flint tube. When the enclosure is filled with fluid under pressure the sack will be eX- panded and stressed and will exert a pressure on the fluid which will be transmitted to the piston or flint within the tube. A small movement in the wall of the sack will correspond to a much larger movement in the flint or, piston and flint, in the tube.

In a preferred arrangement however the first and second members are plungers which slide in communication with the enclosure and the source of resilient pressure is a spring. For example, the first member may be a piston sliding in a larger diameter portion of a tubular flint tube and tending to move in one direction under the action of a helically coiled compression spring towards another piston forming the second member behind a flint in a smaller diameter portion of the flint tube. The enclosure is then spaced between the two pistons within the tub. Although this construction has certain advantages it prevents the flint occupying substantially the full length of the flint guide and in order to utilise the space within the guide as economically as possible, the first member is preferably an annular piston which encircules the flint and slides within an outer sleeve and the spring is a helically coiled compression spring occupying an annular space between the outer sleeve and an inner sleeve which is arranged to hold the flint. The second member is then formed by a plunger which may be the flint itself or a piston which follows the flint. When the flint itself forms the second member, it will act as a plunger extending through a wall of the enclosure and a seal between the flint and enclosure wall may then be provided by an O-sealing ring through which the flint rubs as it is consumed. The flint may be coated with a thin layer of P.T.F.E. or other suitable material so that a smooth surface is presented to the inner periphery of the O-sealing ring. When a piston is provided in the inner sleeve to act as a flint follower; the inner sleeve may be fixed within the outer sleeve.

The fluid through which the pressure is transmitted between the first and second members may be a gas, particularly air, but may also be a substantially incompressible liquid. Thin oil is preferred although water is extremely convenient because, in the event of slight leakage, it is not oily and will not clog the moving parts of the igniting mechanism of the lighter and will evaporate away fairly readily. In addition, it does not attack rubber from which seals may be made and it is not very volatile so that its vapour pressure is not unduly susceptable to temperature changes. An additive may have to be added to the water however for anti-freeze and lubrication purposes.

Although the flint guide may be arranged to be recharged with the new flint through its upper end adjacent the abrasive element after separation if necessary of the abrasive element from the top end of the flint guide, the guide may be provided with a separate inner sleeve which supports the flint within the guide and which is withdrawn through the lower end of the guide remote from the abrasive element so that the sleeve can be recharged with a flint and the sleeve reinserted into the guide again. In this case, when the fluid in the enclosure is air, the sleeve may be so arranged that when the sleeve is withdrawn from the bottom of the flint guide the volume of the enclosure is increased and subseqeuntly opened to the atmosphere. Upon reinsertion of the sleeve, with the new flint, the chamber is first sealed and the air which forms the gas in the enclosure, is then compressed. This is a particularly convenient arrangement because, in

the event of the air in the enclosure leaking from the enclosure, past a worn or slightly faulty seal over a long period of time, so that the flint is urged into engagement with the abrasive element with insufficient force, all that is necessary is to remove the sleeve from the bottom of the flint guide and to reinsert it again to provide the enclosure with a new charge of compressed air.

The flint guide may be a permanent fixture in the lighter or it may form a separate sub-assembly, which is removable and possibly disposable, in which case it may be arranged to be mounted in a tubular housing extending through a fuel reservoir of a cigarette lighter. This arrangement is particularly convenient when the sealed enclosure contains liquid. A flint may be retained within the separate guide sub-assembly prior to use by a number of fingers which overlie the open end of the flint guide through which the flint will project into engagement with the abrasive element in use, the fingers being arranged to be engaged and moved from their overlying position to release the flint by a cam surface, for example part of a cigarette lighter bridge as the sub-assembly is fitted to the lighter. The sub-assembly may be retained in the tubular housing by means of a simple screw threaded connection between a part of the flint guide and the cigarette lighter casing or by a closure which is secured to the end of the tubular housing remote from the abrasive element.

Two examples of flint guides constructed in accordance with the present invention are illustrated in the accompanying drawings in which:

FIGURE 1 shows the first example in central axial section mounted as a removable element in part of a cigarette lighter;

FIGURE 2 is a diagrammatic view but of a lighter incorporating the first example; and,

FIGURE 3 is a view similar to FIGURE 1, but of the second example mounted as a permanent fixture in part of a lighter.

The flint guide which is shown in FIGURE 1 is mounted in an open ended tubular housing 4 which extends right through and is sealed to the upper and lower walls 5 and 6 of the fuel reservoir 7 of a lighter which may be petrol or gas burning. The lighter, as shown in FIG- URE 2, has an outer casing 8, a hinged lid 9, a manually rotatable thumb flint wheel 10 and a bridge 11.

The flint guide itself consists of an outer sleeve formed by a deep drawn cup shaped lower part 12 and a turned upper part 13. A rim 14 at the upper end of the lower part 12 is upset into an annular groove 15, the lower flank of which forms a shoulder, at the bottom of the upper part 13 to secure the two parts together. Within the outer sleeve is a cylindrical open ended inner sleeve 16 the upper end of which is located in a recess 17 at the top of the upper part 13 and the lower end of which is loosely located in a depression 18 drawn in the bottom of the lower part 12. An annular piston 19 slides in the space between the inner sleeve 16 and the lower part 12 of the outer sleeve and has O-sealing rings 20 and 21 which rub over the outer and inner sleeves respectively. A second piston 22 fitted with a peripheral O-sealing ring 23 slides upwards and downwards in the inner sleeve 16 and acts as a follower for a flint 24 mounted within the inner sleeve and projecting from the upper end of the flint guide into engagement with the flint wheel 10.

A helically coiled compression spring 25 is also mounted in the annular space between the inner and outer sleeves, one end of the spring abutting against a shoulder 26 in the upper part 14 of the outer sleeve and the other end against the top of the annular piston 19. A sealed enclosure 27 which is filled with thin oil during assembly, is formed below the annular piston 19 between the sleeves, and within the inner sleeve 16 beneath the piston 22. The spring 25 continually urges the annular piston 19 downwards to try to compress the oil and this pressure is transrnitted to the piston 22 and hence to the flint 24. The annular fi' a f he bottom of the piston 19 is approximately six times as large as the effective area of the lower surface of the piston 22 so that as the flint 24 is consumed, the piston 19 moves approximately one sixth of the distance that the piston 22 moves. This means that during the consumption of a flint 24 substantially as long as the full length of the flint guide, the spring 25 extends by only of this length and since this is a small fractional increase in the length of the spring, it corresponds to a small fractional change in the force urging the flint 24 out of the flint guide.

In order to replenish the lighter with a new flint after a flint has been used up, the flint guide is removed from the tubular housing by removing a bottom piece 28 of the outer casing 8, gripping a knurled tubular finger piece 29, which is screwed onto an adaptor 29' that is a force push fit over the portion 18 of the part 12, and rotating the flint guide so that an externally screw threaded nose 30 on the top of the turned part 14 screws out of a tapped plate 31 which is welded over the opening in the bridge 11. A new flint 24 may be inserted through the open upper end into the inner sleeve 16 of the flint guide which is reassembled in the tubular housing again. Alternatively, the flint guide may be thrown away and replaced by a new one already containing a new flint and a charge of oil in its enclosure 27.

By fitting the flint guide with a tubular finger piece 29 of a different axial length, the guide can be adapted very easily for mounting in a lighter of a different overall size. In this way a standard flint guide can be used with a wide range of lighters.

A port 32 is provided in the wall of the part 12 of the outer sleeve. The purpose of this is to ensure that the guide does not become overfilled with oil. During assembly the enclosure 27 is sealed as soon as the piston 19 passes the port 32 through which excess oil could previously overflow.

The second example which is illustrated in FIGURE 3, uses air instead of oil to transmit the pressure between the first and second members and it is arranged to be fitted as a fixture in a cigarette lighter rather than as a removeable or disposable element. However, like the first example, it can be used equally well with a petrol or gas burning cigarette lighter and will be fitted in a lighter in a similar manner to that shown in FIGURE 2.

This example has an outer sleeve 33 which extends right through and is welded to the upper and lower walls 5 and 6 of the fuel reservoir 7, and projects above the upper wall 5 immediately beneath the flint wheel 10 of the lighter. Within the sleeve 33 is an internal sleeve 34 for supporting a flint 35. The bottom of the sleeve 34 is closed and the top of the sleeve terminates within the sleeve 33 in the form of an enlarged head 36 having an outer peripheral annular groove 37 containing an O-sealing ring 38 which rubs over the inner wall of the sleeve 33.

At its lower end the sleeve 34 has a downwardly projecting central spigot 39 on which an axially moveable closure cap 40 which screws onto the lower end of the sleeve 33, is captive. The movement of the cap 40 is limited by the head of the screw 41 which screws into a tapped opening in the end of the spigot 39.

A helically coiled compression spring 42 surrounds the sleeve 34 and its ends abut one against the closure cap 40 and the outer against the under side of the head 36.

At its upper end adjacent to the flint wheel 10, the sleeve 33 has a neck 43 which extends with a clearance through a hole in the bridge 11 of the lighter. Two 0- sealing rings 44 are mounted in the neck 43 in axially spaced grooves formed one between an annular shoulder 45 and an annular washer 46 and the other between the washer 46 and a gland nut 47 which screws into the top of the neck 43. These 0 rings 44 rub over the external surface of the flint 35.

In order to recharge the guide with a new flint, the closure cap 40 is unscrewed from the bottom of the sleeve 33, when necessary after removing a bottom 28 of the outer casing 8 of the lighter, and the sleeve 34 is withdr-awn from the guide. A flint 35 approximately half as long again as the sleeve 34, is then inserted loosely into the sleeve through its open upper end and the sleeve 34 is reinserted into the sleeve 33. As the sleeve 34 is pushed in, the projecting portion of the flint 35 rubs through the O-sealing rings 44 and finally projects out of the neck 43 at the upper end of the guide into engagement with the flint wheel 10.

A sealed air-filled enclosure 48, the Volume of which is decreased as the sleeve 34 and new flint 35 are inserted into the sleeve 33, is formed within the sleeve 33 above the head 36 at the top of the sleeve 34 and below the lowermost O-sealing ring 44 in the neck of the guide and also within the sleeve 34 both beneath the flint 35 and in the annular clearance between the flint and the sleeve. The spring 42 continually urges the sleeve 34 to move upwards Within the guide relatively to the closure nut 40 so that the air in the enclosure 48 is maintained under pressure and the air pressure acting on the bottom of the flint continually urges the flint 35, which forms a plunger through the two O-sealing rings 44 into engagement with the flint wheel 10.

The upper face of the head 36 forms an annular piston and the annular area exposed to the enclosure 48 is approximately ten times greater than the effective area of the bottom of the flint 35 exposed to the enclosure 48 so that the fractional increase in the length of the spring is approximately throughout the full consumption of a flint substantially as long as the guide itself. During the consumption of the flint 35 the pressure with which it is urged into engagement with the flint wheel 10 does not therefore vary by more than approximately 10% and this is insuflicient to elfect the satisfactory working of the igniting mechanism. In the event of leakage of air from the enclosure 48 over a long period, all that is necessary to refill the chamber with compressed air is to unscrew the cap 40, withdraw the sleeve 34 and the flint 35 from the sleeve 33 and to reinsert them securely once again.

I claim:

1. In a cigarette lighter which comprises a fuel reservoir, an abrasive element, a flint guide, and means urging a flint along said flint guide into engagement with said abrasive element; the improved flint guide and urging means which comprises means defining a sealed enclosure, a mass of fluid under super atmospheric pressure within said enclosure, first and second members movable in communication with said enclosure, resilient means urging said first member to move in a direction to compress said fluid in said enclosure whereby said second member is urged to move under the pressure of said fluid in said enclosure and said flint is urged out of said guide against said abrasive element, the aggregate etfective area of said first member exposed to said enclosure perpendicular to its direction of movement being greater than that of said second member.

2. A cigarette lighter according to claim 1, comprising first and second plungers sliding in communication with said enclosure and forming said first and second members, and a spring forming said resilient means.

3. A cigarette lighter according to claim 1, comprising an outer sleeve, an inner sleeve within said outer sleeve and adapted to hold said flint, an annular piston forming said first member and encircling said flint and sliding within said outer sleeve, and a helically coiled compression spring forming said resilient means and positioned between said outer sleeve and said inner sleeve.

4. A cigarette lighter according to claim 3, further comprising means axially locating said inner sleeve within said outer sleeve and a piston flint follower sliding within said inner sleeve and forming said second member.

5. A cigarette lighter according to claim 4, wherein said fluid is a substantially incompressible liquid.

6. A cigarette lighter according to claim 1, comprising an outer deep drawn cup shaped cylindrical part, a tubular turned part, an annular shoulder on said turned part, a rim portion of said cup shaped cylindrical part upset over said annular shoulder rigidly to interconnect said cup shaped cylindrical part and said turned part in axial alignment, an inner sleeve coaxially within said cup shaped cylindrical part and said turned part, upper and lower ends of said inner sleeve, a part of said turned part locating said upper end of said inner sleeve, wall parts defining a depression in the base of said cup shaped cylindrical part and locating said lower end of said inner sleeve, an annular piston sliding between said inner sleeve and said cup shaped cylindrical part, a piston flint follower sliding within said inner sleeve, a helically coiled compression spring mounted around said inner sleeve and urging said annular piston towards the bottom of said cup shaped cylindrical part a continuous mass of oil beneath said annular piston and said piston flint follower.

7. The invention according to claim 6, further compressing an externally screw threaded nose on said turned part and a tapped opening in a part of said lighter adapted to receive said nose to locate said flint guide in position.

8. The invention according to claim 6, further comprising atubular extension piece fitted externally over said wall parts defining said depression in said base of said cup shaped cylindrical part.

9. A cigarette lighter according to claim 1, further comprising a tubular housing extending through said fuel reservoir of said cigarette lighter and means detachably locating said flint guide and urging means within said tubular housing.

10. A flint feeding mechanism for a cigarette lighter, said mechanism comprising a flint guide, a sealed enclosure containing fluid, resilient means applying pressure to the fluid in said enclosure, and means transmitting to a flint in said flint guide the pressure applied to said fluid.

11. A flint feeding mechanism as claimed in claim 10 in which said resilient means applies pressure to an area of said enclosure larger than the area thereof through which pressure is applied to said pressure transmitting means.

References Cited UNITED STATES PATENTS 3,246,490 4/1966 Quandt 67-7.14

EDWARD J. MICHAEL, Primary Examiner. 

10. A FLINT FEEDING MECHANISM FOR A CIGARETTE LIGHTER, SAID MECHANISM COMPRISING A FLINT GUIDE, A SEALED ENCLOSURE CONTAINING FLUID, RESILIENT MEANS APPLYING PRESSURE TO THE FLUID IN SAID ENCLOSURE, AND MEANS TRANSMITTING TO A FLINT IN SAID FLINT GUIDE THE PRESSURE APPLIED TO SAID FLUID. 